Python escaping sed and bash command with subprocess

Question

Question:

How do I use sed with python successfully? I have to run this command on a remote server to get a list of comma delimited hosts. When ran from bash I get what I want which is something like host1, host2, host3

Here is what I have:

process = subprocess.Popen(["ssh $USER@mychefserver knife search node "chef_environment:*" | grep -i "node name" | egrep -i "stuff|ruff" | uniq -u | sort -n | cut -d ":" -f 2 | sed -e 's/^[ \t]*//' | tr '\n' ', '
"], shell=False, stdout=PIPE)

I know I'll have to escape the \\n, \\t, etc, but I'm having trouble with the rest. Whenever I try to run it from my Python script I get an error for invalid syntax even though I've tried a cornucopia of escapes.

Answer 1

如你使用字符串引用坏了"双引号字符串中，你必须逃离"像\\" 。此外应注意，大多数在命令行中的双引号可以用单引号替换' 。下面的代码应该工作：

process = subprocess.Popen(["ssh $USER@mychefserver knife search node \"chef_environment:*\" | grep -i 'node name' | egrep -i 'stuff|ruff' | uniq -u | sort -n | cut -d':' -f 2 | sed -e 's/^[ \t]*//' | tr '\n' ', '"], shell=False, stdout=subprocess.PIPE)